This invention relates generally to security apparatus and more specifically to a device for preventing access to an interconnection joint between two members without breaking a seal thereby providing an indication of the integrity of the seal.
There are many industries in which it is desired to prevent tampering with interconnection joints. For example, tampering with well head distribution valving, gas meter coupling nuts, gas line fittings, hose and pipe connections and electrical wiring and communication connections to name but a few.
Conventional apparatus to provide such security have included various interfitting lockable structures such as a two-part housing hinged together to enclose an interconnection joint and fastened together using a conventional lock or wire seal such as shown in U.S. Pat. Nos. 3,009,483; 4,826,215 and 5,092,631. Other devices have included two plastic halves that join together to form a permanent enclosure of a joint or coupling which requires destruction of the structure to obtain access to the joint or coupling. Examples of these devices are shown in U.S. Pat. Nos. 4,405,161; 4,600,200 and 4,372,593. These devices, generally have been effective in serving their intended function; however, the configuration of the locking members have been relatively complex and expensive to produce.
It is an object of the present invention to provide a simple device which is adapted to sealingly enclose an interconnection joint which can only be removed by breaking the seal.
Another object is the provision of such a device which is easily installed, reliable and yet of low cost.
These, together with other objects and advantages which will become subsequently apparent, reside in the details of construction and operation as more fully described and claimed, reference being made to the accompanying drawings which form a part thereof wherein the reference numerals refer to like parts throughout.
Briefly, in accordance with the invention, first and second generally hollow cylindrical halves of a hard plastic material are joined together by a living hinge. The halves are pivotable to form an enclosure and are provided with apertures in each end face to accommodate reception of an interconnection joint or coupling of first and second members within the enclosure with the members extending out through respective apertures. One half is formed with a lip means extending outwardly and the other half is formed with lip means extending inwardly with the two lip means adapted to pass beyond one another in spaced facing relation when the halves are closed. A locking pin is then received in a channel forming the space between the two lip means. A plurality of detents are formed on the lip means or the locking pin which are adapted to lockingly engage with a corresponding plurality of projections formed in the other of the lip means and the locking pin.
According to a feature of the invention, the detents and projections each are formed with a surface which lies in a plane perpendicular to the longitudinal axis of the cylinder and a second inclined surface which enables the pin to be inserted between the two lip means at one end of the channel wedging them apart until the projections are received within the detents with the surfaces perpendicular to the longitudinal axis preventing outward movement of the pin. The opposite end of the channel is closed by a wall to prevent access from that end thereby preventing removal of the pin without fracturing the housing.